How to select pool equipment - Further Reading

Revision as of 17:00, 30 March 2020 by ajw22 (talk | contribs) (→‎Replacing a single speed pump in an existing pool)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Important Warranty Information When Selecting Equipment

Pool equipment manufactures have been changing their warranties on various product lines frequently. Prior to purchase, confirm your understanding of all warranty information and details.

Review a manufacturer’s position on warranties. How do internet sales and/or owner installation affect the warranty? Identify whether the equipment manufacturer warranty requires the equipment to be installed by a certified professional or if a pool owner can perform the installation and have warranty coverage. Some manufacturers offer longer warranties when you buy a bundle of equipment together and have it professionally installed. Understand what product registration is required for warranty coverage.

Selection of Equipment

Equipment selection for pools is dependent on the volume of water in the pool, pool use, pool features, and how much technology or automation is chosen. It is also recommended to become familiar with pool industry terminology (if you are relatively new to the discussion), and any changes or advancements that have been made since your last purchase.

For a new pool in general, a big cartridge filter, a big variable speed pump, a SWCG and automation are good choices.

How to select the best pump for a new pool

Sizing a pump depends in large part on what its intended use will be. Will the pool have water features (sheer descents, deck jets, etc.) or an integrated spa?

Variable Speed Pump Electrical Costs.jpg

In the United States, variable speed (VS) motors will be required for all pumps over 1.1 total HP as of July 18, 2021.[1] Purchasing a single speed pump or a 2-speed pump now for a new pool is discouraged.

Variable speed pumps are built with over-capacity in mind. For example, a smaller pool, with water features or spa, should have a full-size VS pump. A large pool with many features may need multiple VS pumps. A VS pump can easily be set to pump the flow you need for each purpose, from low rpm for regular filtering and to skim the surface to high rpm for a spa or water features.

If the pool is to have no water features or an integrated spa, then one of the lower HP VS pumps is sufficient. This is because at most times a lower flow will be sufficient to skim the surface, but a higher flow can be used for vacuuming or other specific needs.

The chart to the right shows energy cost at different speeds for a VS pump.

You will find a deeper discussion about Pump Basics in TFP Pool School.

Replacing a single speed pump in an existing pool

If you are replacing a single speed pump in an existing pool until the July, 2021 regulation becomes effective consider that a 2-speed pump will save you almost as much as a VS pump. VS pumps do not operate the same way as a single speed or 2-speed pumps so they are more energy efficient, but not all that much. And, they cost a lot more.

VS pumps are best when you have a spa or a number of water features, and you want to run at different RPMs throughout the day.. For a standard pool owner, a 2-Speed pump will work just fine.

Selecting the best pool filters

You should get the largest filter you can afford and that will fit onto your equipment pad. The larger the filter, the less it needs to be cleaned. All filter types work by capturing the stuff that falls into the pool and floats on the pool surface. Depending on where you live, availability of water, cost of water, and if your pool is open year-round can influence what type of filter is best for your environment.

The cost of the filter only increases marginally from a small size to the largest size. In general, and discussed more below, the larger the filter the better to increase time between filter cleanings and reduce water used for filter cleaning.

Many sites stress ‘turnover’ when sizing filters. TFP has shown that turnover is not a factor in maintaining your pool water. Proper pool water chemistry and sufficient filtering (skimming) to remove the stuff that falls into the pool is what keeps your pool water TFP clear.

Pool Filter Types

  • Sand filters are the simplest. Most pools should use a minimum of a 24” sand filter with pools greater than 25,000 gallons or in high debris areas using a 30” filter. Sand filters use lots of water to clean them. Therefore you should select a large sand filter that will need less frequent backwashing, and thus use less water.
  • DE (diatomaceous earth) filters are a bit more complex but also use lots of water to clean and need to be refilled with DE or an alternative media. The filter sizing is in Square Feet (SF) of filter area. Minimum size of 48 SF for most pools. Pools larger than 25,000 gallons should use a 60 SF filter. This again is based reducing the backwash/cleaning frequency of the filter and thus reducing water and DE or alternative media use.
  • Hybrid DE filters use a cartridge element with DE added. They can be backwashed but are typically broken down and cleaned instead of backwashed, and thus use less water during cleaning. A minimum size of 80SF is recommended with larger pools using the 100SF models. The available Hybrid DE filters come in a few sizes. Larger, again, is always best to reduce cleaning intervals.
  • Cartridge filters use little water when being cleaned as you remove the cartridges and clean them using a hose sprayer. The cartridges do need to be replaced every few years. For most pools a cartridge filter is a great choice. The filter sizing is in Square Feet (SF) of filter area. At a minimum you want 200SF/10,000 gallons of pool volume. Some Pool Builders or websites recommend much smaller filter sizes. But for more efficient operation and less cleaning of the cartridges, more filter area is better.

Pool Filter Comparison in TFP Pool School has a more in-depth discussion about filters.

Selecting pool heaters

There are two types of heaters typically used in pools and spas:

  • Gas heaters using natural gas or propane energy
  • Heat Pumps using electricity energy

There are also resistive electric small pool and spa water heaters that have low BTU output and use high amounts of electricity. They may be used in special circumstances where electric energy is no cost or very low cost.

Pool Heaters Explained in TFP Pool School discusses more about pool heaters.

Sizing

Sizing of a pool heater depends on many factors including your climate, pool location, size of pool, temperatures you want the pool or spa heated to, if the pool is covered, and type of energy available - natural gas, propane (which can be expensive), or electric.

Pools that need quick heat or have spas should use a gas heater. For pools in areas that need heat nearly all of the swim season or are located in warmer climates that wish to extend the season an electric heat pump may be applicable.

Air Temperature

Heat pumps only work when ambient air temperature is above 50-degree F. Heat pump BTU ratings are typically based on 80F air temperature. As the air temperature drops the BTU heating output will drop until most Heat Pumps shut down at 50F.

As the variables for sizing a heater are so wide, we suggest speaking to a pool heater sales representative and posting on the forum for recommendations.

About BTUs

The science of heating water is that it takes one British Thermal Unit (BTU) of energy to raise one pound of water one-degree Fahrenheit. Water weighs 8.4 pounds per gallon. So, from the BTU output of a heater being proposed you can determine how long it will take to heat your pool. We suggest using an 80% efficiency factor for a gas heater, 100% for a Heat Pump, in the calculation. This efficiency factor encompasses all losses, not just what occurs at the heater.

Calculators has various tools you can use to determine the best type and size of heater for your pool.

Chlorinating Your Pool Water

How to Chlorinate Your Pool in TFP Pool School discusses the alternatives you have to keep your pool water sanitary.

Saltwater Chlorine Generators

Salt Water Chlorine Generators (SWCG) are widely used by TFP members. The main thing to remember in sizing is to get a SWCG that is rated for at least 2X your pool volume. That way you will not need to run your pump 24 hours per day and/or your SWCG at 100% setting to chlorinate your pool.

For example, a 20,000-gallon pool should have a SWCG rated for a 40,000-gallon pool. A SWCG is also rated in pounds of chlorine gas per 24 hours. A rating of 1.4 pounds is sufficient for a 20,000-gallon pool.

Salt Water Chlorine Generators in TFP Pool School explains how SWCGs work and are maintained.

Liquid Chlorine Dispensers

Tanks with a chemical pump are available that can be used to add liquid chlorine to a pool. We suggest making sure the tank will hold a minimum of 5-7 days liquid chlorine use so you can go that long between filling the tank.

Automation

Most automation systems sold by pool equipment manufacturer’s work best when the automation system, pump(s), lights and SWCG (if installed) are from the same manufacturer.

Programming, control, etc. are far simpler and straightforward when all items are from the same manufacturer. Do realize that even with that, not all pumps from a manufacturer can be controlled by their automation. An example is the Pentair Superflo VS pump whose variable speeds cannot be controlled by an automation system, even Pentair’s.

Some automation systems can control other manufacturer pumps and lights, but in general it is not advised to mix pumps and lights from different manufacturers.

Most pool heaters can be mixed with any automation system since they are turned on and off by the automation using a standard method based on the pool water temperature.

Filters can be mixed with any automation system as they are not controlled.